Heterozygous CAPZA2 mutations cause global developmental delay, hypotonia with epilepsy: a case report and the literature review.

CAPZA2 encodes the α2 subunit of CAPZA, which is vital for actin polymerization and depolymerization in humans. However, understanding of diseases associated with CAPZA2 remains limited. To date, only three cases have been documented with neurodevelopmental abnormalities such as delayed motor development, speech delay, intellectual disability, hypotonia, and a history of seizures. In this study, we document a patient who exhibited seizures, mild intellectual disability, and impaired motor development yet did not demonstrate speech delay or hypotonia. The patient also suffered from recurrent instances of respiratory infections, gastrointestinal and allergic diseases. A novel de novo splicing variant c.219+1 G > A was detected in the CAPZA2 gene through whole-exome sequencing. This variant led to exon 4 skipping in mRNA splicing, confirmed by RT-PCR and Sanger sequencing. To our knowledge, this is the third study on human CAPZA2 defects, documenting the fourth unambiguously diagnosed case. Furthermore, this splicing mutation type is reported here for the first time. Our research offers additional support for the existence of a CAPZA2-related non-syndromic neurodevelopmental disorder. Our findings augment our understanding of the phenotypic range associated with CAPZA2 deficiency and enrich the knowledge of the mutational spectrum of the CAPZA2 gene.

Clinical and genetic analysis of benign familial infantile epilepsy caused by PRRT2 gene variant.

Objective: This study presents the clinical phenotypes and genetic analysis of seven patients with benign familial infantile epilepsy (BFIE) diagnosed by whole-exome sequencing. Methods: The clinical data of seven children with BFIE diagnosed at the Department of Neurology, Children's Hospital Affiliated to Zhengzhou University between December 2017 and April 2022 were retrospectively analyzed. Whole-exome sequencing was used to identify the genetic causes, and the variants were verified by Sanger sequencing in other family members. Results: The seven patients with BFIE included two males and five females ranging in age between 3 and 7 months old. The main clinical phenotype of the seven affected children was the presence of focal or generalized tonic-clonic seizures, which was well controlled by anti-seizure medication. Cases 1 and 5 exhibited predominantly generalized tonic-clonic seizures accompanied by focal seizures while cases 2, 3, and 7 displayed generalized tonic-clonic seizures, and cases 4 and 6 had focal seizures. The grandmother and father of cases 2, 6, and 7 had histories of seizures. However, there was no family history of seizures in the remaining cases. Case 1 carried a de novo frameshift variant c.397delG (p.E133Nfs*43) in the proline-rich transmembrane protein 2 (PRRT2) gene while case 2 had a nonsense variant c.46G > T (p.Glu16*) inherited from the father, and cases 3-7 carried a heterozygous frameshift variant c.649dup (p.R217Pfs*8) in the same gene. In cases 3 and 4, the frameshift variant was de novo, while in cases 5-7, the variant was paternally inherited. The c.397delG (p.E133Nfs*43) variant is previously unreported. Conclusion: This study demonstrated the effectiveness of whole-exome sequencing in the diagnosis of BFIE. Moreover, our findings revealed a novel pathogenic variant c.397delG (p.E133Nfs*43) in the PRRT2 gene that causes BFIE, expanding the mutation spectrum of PRRT2.

[Phenotypic and genetic analysis of a child with partial trisomy 7q].

OBJECTIVE: To define the nature and origin of a chromosomal aberration in a child with unexplained growth and development retardation, and to analyze its genotype-phenotype correlation. METHODS: A child who had presented at the Affiliated Children's Hospital of Zhengzhou University on July 9, 2019 was selected as the study subject. Chromosomal karyotypes of the child and her parents were determined with routine G-banding analysis. Their genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array). RESULTS: Karyotyping analysis combined with SNP array suggested that the chromosomal karyotype of the child was 46,XX,dup(7)(q34q36.3), whilst no karyotypic abnormality was found in either of her parents. SNP array has identified a de novo 20.6 Mb duplication at 7q34q36.3 [arr[hg19] 7q34q36.3(138335828_158923941)×3] in the child. CONCLUSION: The partial trisomy 7q carried by the child was rated as a de novo pathogenic variant. SNP array can clarify the nature and origin of chromosomal aberrations. Analysis of the correlation between genotype and phenotype can facilitate the clinical diagnosis and genetic counseling.

Paternal uniparental disomy of chromosome 16 resulting in homozygosity of a GPT2 mutation causes intellectual and developmental disability.

Recessive mutations in glutamate pyruvate transaminase 2 (GPT2) have recently been found to be associated with intellectual and developmental disability (IDD). In this study, we discovered a homozygous missense variant, NM_133443: [c.1172C > T, p. Pro391Leu], of GPT2 on chromosome 16 in a proband diagnosed with IDD through trio whole-exome sequencing (WES). The pathogenicity of the variant was further verified by bioinformatics analysis and functional studies in vitro. This autosomal recessive disease was caused by paternal uniparental disomy (UPD) which was further proven by single nucleotide polymorphism array (SNP array). In past literature, recessive diseases in chromosome 16 were usually due to maternal UPD where Mendel's law of inheritance was not applicable. However, in our case we found that paternal UPD can cause recessive diseases related to the GPT2 gene on chromosome 16. Our study provides an important line of evidence for the diagnosis of GPT2-related intellectual developmental disorders.

[Analysis of NF1 gene variants among thirteen patients with neurofibromatosis type 1].

OBJECTIVE: To detect variants of NF1 gene among thirteen patients with neurofibromatosis type 1. METHODS: Genomic DNA was extracted from peripheral blood samples of the patients. High-throughput sequencing was employed to detect potential variants of the NF1 and NF2 genes. RESULTS: Thirteen pathogenic variants were identified among the patients, which included one NF1 deletion, three missense variants, three nonsense variants and six frameshifting variants. Among these, 10 variants have been associated with neurofibromatosis type 1. c.4180A>T (p.Asn1394Tyr), c.4217dupT (p.Leu1406fs) and c.1753dupT(p.Leu585Phefs*3) were unreported previously. Based on the guidelines of the American College of Medical Genetics and Genomics, c.4180A>T (p.Asn1394Tyr) was predicted to be likely pathogenic (PS2+PM1+PM2+PP2), while c.4217dupT (p.Leu1406fs) and c.1753dupT (p.Leu585Phefs*3) were predicted to be pathogenic (PVS1+PS2+PM2). CONCLUSION: Variants of the NF1 gene probably underlay the disease among these children. Above findings have enriched the the spectrum of NF1 gene variants.

[Analysis of a Chinese pedigree with autosomal dominant Charcot-Marie-Tooth disease type 2A2A].

OBJECTIVE: To explore the genetic basis of a pedigree affected with peroneal muscular atrophy. METHODS: Neuroelectrophysiological examination and whole exome sequencing were carried out for the proband, a six-year-and-ten-month-old boy. Suspected variant was verified in his family members through Sanger sequencing. Bioinformatic analysis was carried to predict the conservation of amino acid sequence and impact of the variant on the protein structure and function. RESULTS: Electrophysiological examination showed demyelination and axonal changes of motor and sensory nerve fibers. A heterozygous missense c.1066A>G (p. Thr356Ala) variant was found in exon 11 of the MFN2 gene in the proband and his mother, but not in his sister and father. Bioinformatic analysis using PolyPhen-2 and Mutation Taster software predicted the variant to be pathogenic, and that the sequence of variation site was highly conserved among various species. Based no the American College of Medical Genetics and Genomics standards and guidelines, the c.1066A>G (p. Thr356Ala) variant of MFN2 gene was predicted to be likely pathogenic (PS1+ PM2+ PP3+ PP4). CONCLUSION: The heterozygous missense c.1066A>G (p.Thr356Ala) variant of the MFN2 gene probably underlay the disease in the proband, and the results have enabled genetic counseling and prenatal diagnosis for this family.

[Phenotypic and genetic analysis of a boy with a 10p15.3 deletion and partial trisomy 18p syndrome].

OBJECTIVE: To delineate the nature and origin of chromosomal aberration in a girl with mental retardation. METHODS: Genomic DNA was analyzed by using single nucleotide polymorphism-based array (SNP array). The proband and her parents were subjected to routine G-banded chromosomal karyotyping analysis. RESULTS: SNP array has identified a 1.2 Mb microdeletion at 10p15.3 and a duplication at 18p11.21-pter in the proband. The patient was also found to harbor a structural aberration involving 10p. The karyotype of her father was 46,XY,t(10;18)(p15;p11.2), while her mother was found to be normal. CONCLUSION: The structural aberration of 10p carried by the patient has derived from her father whom has carried a balanced translocation of t(10;18). Her karyotype was finally determined as 46,XX,der(10)t(10;18)(p15;p11.2)pat. The abnormal phenotype of the patient can probably be attributed to the presence of 10p15.3 microdeletion and 18p11.21-pter duplication.

[Phenotypic and genetic analysis of a boy with partial trisomy of 22q].

OBJECTIVE: To delineate the nature and origin of chromosomal aberration in a boy with mental retardation and multiple congenital deformities. METHODS: Chromosomal karyotypes of the proband and his parents were determined by routine G-banding analysis. Genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array). RESULTS: The karyotype of the proband was 46,X,add(Y)(q11.23). No karyotypic abnormality was detected in either parent. SNP array has identified a de novo 21.6 Mb duplication at 22q12qter in the proband. CONCLUSION: The de novo 22q12qter duplication probably underlies the abnormalities in the proband.

[Clinical and genetic analysis of a case with infantile Parkinsonism with motor delay due to tyrosine hydroxylase deficiency].

OBJECTIVE: To explore the clinical characteristics and genetic variants in a child with tyrosine hydroxylase-deficient infantile Parkinsonism with motor delay. METHODS: Clinical feature of the patient was summarized. Genomic DNA was extracted from peripheral blood samples taken from the child and her family members. All exons of GCH1, TH and SPR genes were subjected to targeted capture and next-generation sequencing. Suspected variants were verified by Sanger sequencing. RESULTS: The child could not sit alone at 7 month and 11 days. Physical examination suggested motor retardation and hypotonia, limb stiffness, head nodding, slight torticollis, and language and intellectual developmental delays. She developed involuntary shaking of limbs at 3 month old, which lasted approximately 10 seconds and aggregated with excitement and before sleeping. Cranial MRI revealed widening of subarachnoid space on the temporomandibular and particularly temporal sides. Genetic testing revealed that she has carried a nonsense c.457C>T (p.R153X) variant, which was known to be pathogenic, and a novel missense c.720C>G (p.I240M) variant of the TH gene. The two variants were derived from her father and mother, respectively. CONCLUSION: The child was diagnosed as tyrosine hydroxylase-deficient infantile Parkinsonism with motor delay due to compound heterozygous variants of the TH gene. Above finding has enriched the spectrum of TH gene variants.

[Clinical and genetic study of a child with delayed language development carrying ring 22 and a 22q13 microdeletion].

OBJECTIVE: To explore the genetic basis for a child featuring delayed language development. METHODS: The patient was subjected to conventional G-banding chromosomal karyotyping and single nucleotide polymorphism microarray (SNP array) analysis. RESULTS: The karyotype of the child was 46, XY, r(22)(p11.2q13). SNP array analysis has identified a hemizygous 1.67 Mb deletion at 22q13 (arr [Hg19]22q13.33 (49 531 302-51 197 766)×1). CONCLUSION: The child has carried a ring 22 in addition with a 22q13 microdeletion. The results may provide clues for her condition and genetic counseling for the family.

Genomic and biological characterization of a pandemic norovirus variant GII.4 Sydney 2012.

Genogroup II, genotype 4 noroviruses (GII.4 NoVs) are a leading cause of epidemic and sporadic acute non-bacterial gastroenteritis worldwide. In this study, we isolated a GII.4 NoV strain (designated 2015HN08) from a kid presenting with acute gastroenteritis and determined its near-complete genome sequence. We then performed sequence analysis by comparing this strain with the prototypical GII.4 strain. Virus-like particles (VLPs) derived from the major capsid protein (VP1) were expressed by using a recombinant-baculovirus expression system, and monoclonal antibodies (mAbs) were produced to compare changes in antigenic or histo-blood group antigens (HBGAs) binding sites with the previously characterized GII.4 NoV strain (JZ403). The genome of 2015HN08 was 7559 nucleotides (nt) long, excluding the poly(A) tail. Genotyping analysis indicated that this strain was a Sydney 2012 variant. In comparison with the prototype Sydney 2012 strain, there were 74, 35, and 16 differences in nucleotide sequences in ORF1, OFR2, and OFR3, causing 7, 10, and 6 amino acid (aa) changes, respectively. Expression of VP1 led to successful assembly of VLPs, as demonstrated by electron microscopy. Screening of hybridoma cell supernatants with an in vitro VLP-HBGAs binding blockade assay led to the identification of a cell clone 3G10 that exhibited HBGA-blocking effects. This mAb also exhibited blocking effects against JZ403 strain, suggesting maintenance of the antigenic site and/or HBGAs binding sites between the two strains. In summary, we determined the near-complete genome sequence of a GII.4 Sydney 2012 variant and produced an mAb with blocking effects that might be useful in evaluating the evolution of current Sydney 2012 NoV strains.

H19 suppresses the growth of hepatoblastoma cells by promoting their apoptosis via the signaling pathways of miR-675/FADD and miR-138/PTK2.

BACKGROUND: The objective of this study was to clarify the molecular pathways involved in hepatitis B virus (HBV)-induced hepatoblastoma. METHOD: The expression of factors in different signaling pathways (H19, miR-675, miR-138, protein tyrosine kinase 2 [PTK2], fas-associated death domain [FADD], hypoxia-inducible factor 1-alpha [HIFIA], focal adhesion kinase [FAK], caspase-8, and caspase-3) was compared between HBV (+) and HBV (-) groups using quantitative real-time polymerase chain reaction and Western blot analysis. Subsequently, immunohistochemistry (IHC) and TdT-mediated dUTP Nick-End Labeling (TUNEL) assays were used to verify the expression of above proteins in HBV (+) and HBV (-) groups. Computational analysis was conducted to predict the target genes of miR-675 and miR-138, whose regulatory relationships were then clarified using luciferase assays and cell transfection studies. RESULT: The expression of H19, miR-675, PTK2, HIFIA, and FAK was increased in the HBV (+) group, while the expression of miR-138, FADD, caspase-8, and caspase-3 was decreased in the HBV (+) group. FADD and PTK2 were identified as target genes of miR-675 and miR-138, respectively. In addition, miR-675 was upregulated while miR-138 was downregulated by X protein (HBx). CONCLUSION: In summary, the results of this study revealed the molecular pathways involved in HBV-induced hepatoblastoma. In the presence of HBV, HBX upregulated the expression of H19 through HIFIA. Consecutively, overexpressed H19 upregulated the expression of PTK2 via targeting miR-138 and downregulated the expression of FADD via targeting miR-675. Finally, increased expression of PTK2 and reduced expression of FADD both led to the inhibition of cell apoptosis, thus promoting the tumorigenesis of hepatoblastoma.

Gastrodin Rescues Autistic-Like Phenotypes in Valproic Acid-Induced Animal Model.

Autism spectrum disorder (ASD) is an immensely challenging developmental disorder characterized by impaired social interaction, restricted/repetitive behavior, and anxiety. GABAergic dysfunction has been postulated to underlie these autistic symptoms. Gastrodin is widely used clinically in the treatment of neurological disorders and showed to modulate GABAergic signaling in the animal brain. The present study aimed to determine whether treatment with gastrodin can rescue valproic acid (VPA) induced autistic-like phenotypes, and to determine its possible mechanism of action. Our results showed that administration of gastrodin effectively alleviated the autistic-associated behavioral abnormalities as reflected by an increase in social interaction and decrement in repetitive/stereotyped behavior and anxiety in mice as compared to those in untreated animals. Remarkably, the amelioration in autistic-like phenotypes was accompanied by the restoration of inhibitory synaptic transmission, α5 GABAA receptor, and type 1 GABA transporter (GAT1) expression in the basolateral amygdala (BLA) of VPA-treated mice. These findings indicate that gastrodin may alleviate the autistic symptoms caused by VPA through regulating GABAergic synaptic transmission, suggesting that gastrodin may be a potential therapeutic target in autism.

GntR is involved in the expression of virulence in strain Streptococcus suis P1/7.

Streptococcus suis is a severe zoonotic pathogen, responsible for acute diseases in pigs and human. GntR proteins are widely distributed in various bacterial species. In a previous study, GntR proteins were reported to be involved in virulence in many pathogens. To investigate the relationship between GntR and S. suis serotype 2, we constructed an isogenic deletion mutant P1/7ΔgntR and an isogenic single-nucleotide substitution mutant P1/7gntR(SC070731), which took strain P1/7 as parent. The results show that the mutants P1/7ΔgntR and P1/7gntR(SC070731) have a stronger ability to tolerate oxidative stress and to reproduce in blood. Moreover, a higher fatality rate was observed in mice when challenged with P1/7ΔgntR or P1/7gntR(SC070731) compared with that of P1/7. Overall, all results suggest that GntR greatly impacts the virulence of S. suis serotype 2 strain P1/7 and give a new perspective on virulence generation in S. suis.

[Identification of a novel splicing mutation in COL1A1 gene in a Chinese family affected with typeâ osteogenesis imperfecta].

OBJECTIVE: To investigate the genetic cause for a large family affected with typeⅠosteogenesis imperfecta. METHODS: Genomic DNA was extracted from peripheral venous blood samples. The entire coding region and intron-exon boundaries of the COL1A1 gene were subjected to PCR amplification and direct sequencing. Total RNA was also extracted from immortalized B cell lines from the patients, with the first strand of cDNA synthesized with an oligo(dT)18 primer. The PCR products were directly sequenced using the TA cloned plasmid. RESULTS: A c.3208G>A mutation has been identified in the COL1A1 gene, which can alter the splicing pattern of mRNA. CONCLUSION: A novel splicing mutation c.3208G>A of the COL1A1 gene probably underlies the disease.